While differential behavior of modern ciphers in a single secret key scenario is relatively well understood, and simple techniques for computation of security lower bounds are readily available, the security of modern block ciphers against related-key attacks is still very ad hoc. In this paper we make a first step towards provable security of block ciphers… (More)

In this paper we construct a chosen-key distinguisher and a related-key attack on the full 256-bit key AES. We define a notion of differential q-multicollision and show that for AES-256 q-multicollisions can be constructed in time q · 2 67 and with negligible memory, while we prove that the same task for an ideal cipher of the same block size would require… (More)

We propose the TWEAKEY framework with goal to unify the design of tweakable block ciphers and of block ciphers resistant to related-key attacks. Our framework is simple, extends the key-alternating construction, and allows to build a primitive with arbitrary tweak and key sizes, given the public round permutation (for instance, the AES round). Increasing… (More)

We present high probability differential trails on 2 and 3 rounds of BLAKE-32. Using the trails we are able to launch boomerang attacks on up to 8 round-reduced keyed permutation of BLAKE-32. Also, we show that boomerangs can be used as distinguishers for hash/compression functions and present such distinguishers for the compression function of BLAKE-32… (More)

iii Abstract The National Institute of Standards and Technology (NIST) opened a public competition on November 2, 2007, to develop a new cryptographic hash algorithm – SHA-3, which will augment the hash algorithms specified in the Federal Information Processing Standard (FIPS) 180-4, Secure Hash Standard (SHS). The competition was NIST's response to… (More)

In this work, we introduce a new non-random property for hash/compression functions using the theory of higher order differentials. Based on this, we show a second-order differential collision for the compression function of SHA-256 reduced to 47 out of 64 steps with practical complexity. We have implemented the attack and provide an example. Our results… (More)

In this paper we present known-plaintext single-key and chosen-key attacks on round-reduced LED-64 and LED-128. We show that with an application of the recently proposed slidex attacks [7], one immediately improves the complexity of the previous single-key 4-step attack on LED-128. Further, we explore the possibility of multicollisions and show single-key… (More)

At CHES 2013 was presented a new block cipher called Zorro. Although it uses only 4 S-boxes per round, the designers showed the resistance of the cipher against various attacks, and concluded the cipher has a large security margin. In this paper, we give a key recovery attack on the full cipher in the single-key model that works for 2 64 out of 2 128 keys.… (More)

In this paper we analyze the security of systems based on modular additions, rotations, and XORs (ARX systems). We provide both theoretical support for their security and practical cryptanalysis of real ARX primitives. We use a technique called rotational cryptanalysis, that is universal for the ARX systems and is quite efficient. We illustrate the method… (More)

In this work, we apply the rebound attack to the AES based SHA-3 candidate Lane. The hash function Lane uses a permutation based compression function, consisting of a linear message expansion and 6 parallel lanes. In the rebound attack on Lane, we apply several new techniques to construct a collision for the full compression function of Lane-256 and… (More)